Taxonomy: Based on molecular evidence, Gamauf et al. (2005a, 2005b) recommended treating these populations as a separate species from N. philippensis, and Preleuthner and Gamauf (1998) had earlier shown that there are distinct morphological and plumage pattern differences between the two forms. The Asian hawk-eagles were traditionally placed in the genus Spizaetus, but recent molecular studies by Helbig et al. (2005) have shown that the Asian species of the group represent a different lineage from the New World species and should therefore be assigned to a new genus for which the name Nisaetus Hodgson 1836 is available. This general concluson was also supported by the molecular study of Lerner and Mindell (2005), using DNA sequences from one nuclear and two mitochondrial genes. Gamauf et al. (2005b) and Haring et al. (2007) also confirmed that Asian Spizaetus (Nisaetus) species are monophyletic, and are distributed in two sub-clades, one of which consists of N. cirrhatus, N. philippensis, N. pinskeri, and N. lanceolatus. more....

Food and Feeding Behavior: Prey not recorded (Kennedy et al. 2000), but probably feeds on birds (Ferguson-Lees and Christie 2001).

Breeding: No information (Kennedy et al. 2000).

Conservation: This species is not recognized by BirdLife International, but the Philippine Hawk-eagle, including the purported N. pinskeri populations, is designated as Vulnerable. As treated here, the separate species should probably be classified as Endangered. Both taxa are suffering from continuing habitat loss in many parts of their respective ranges and also from hunting and trapping pressure (BirdLife International 2009).

Population Estimates: Ferguson-Lees and Christie (2001) estimated the global population of the N. philippensis, including the populations now assigned to N. pinskeri, as being in the range of 1,001 to 10,000 individuals. Gamauf et al. (2005) pointed out that splitting the hawk-eagle populations of the Philippines into two species would lead to lower estimates of their respective population sizes, which they estimated at 200-220 pairs for N. philippensis on Luzon and 320-340 pairs for N. pinskeri on Mindanao (Preleuthner and Gamauf 1998). BirdLife International (2009) concluded that this leads to a global population estimate for the combined populations of 1,000 to 2,500 individuals.